Added test for pyqtgraph; added .gitignore

.gitignore

+__pycache__/

prototype/pyqtgraph_plot_test/main.py

+import sys
+import random
+from PySide2 import QtCore, QtGui, QtWidgets
+
+import pyqtgraph
+
+class TestWidget(QtWidgets.QWidget):
+
+    def __init__(self, other=None):
+        super().__init__()
+
+        self.plot = pyqtgraph.PlotWidget()
+
+        # Disable zooming on the y-axes.
+        self.plot.setMouseEnabled(y=False)
+
+        if other:
+            # setXLink will link the x-axes of the two plot widgets
+            # There is a corresponding function setYLink if we ever
+            # need to do the same for the y-axes, though for now it does
+            # not seem like something we would need.
+            self.plot.setXLink(other.plot)
+
+        self.layout = QtWidgets.QGridLayout()
+        self.layout.addWidget(self.plot, 0, 0, 1, 1)
+
+        self.setLayout(self.layout)
+
+if __name__ == "__main__":
+    app = QtWidgets.QApplication(sys.argv)
+
+    w = TestWidget()
+    w.resize(800, 600)
+    w.show()
+    # Plot will take in a list, or a numpy array type
+    # May generalize to other iterable types.
+    w.plot.plot([0, 1, 2, 1, 2, 3, 0])
+
+    w2 = TestWidget(w)
+    w2.resize(800, 600)
+    w2.move(500, 500)
+    w2.show()
+    # Plot will not take in iterators, though. So need
+    # to cast this.
+    w2.plot.plot(list(reversed([0, 1, 2, 1, 2, 3, 0])))
+
+    app.exec_()